Buds 56 with460andc-6 Engine issues Help

Iwould like help or advice from anyone on the Big Block Fords.I have put a1973 460 bored .040 over flat top pistons and stock cam in my 1956 ford.I have a set of Dove-c heads with the stainless valves and stellite seats for unleaded fuel.Also placed the Crank out of a 1970 429 in it as the original crank was messed up.in trying to adjust the rockers on the heads I find the valves were not closing and wound up with 2 bent pushrods.took the heads back off and had the valve stem hieght checked every thing O.K. according to the head shop.they suggested using the ARP adustable locing nuts on the Rockers as I cannot get the stock nuts to stay in place when the valves are closing all the way according to a compression check on the cylinders.My question is will the Arp nuts work and is there a bigger issue I should be looking at????:Any advice or suggestions would help I have been reading other articles and have seen one or two that seem to have the same issues Thank you for any advice as Im pulling what hair I have out.I figured by now to be driving Ole Yeller and having fun.Recieved the arp nuts today placed them in the heads and adjusted to the best sounding cylinders as it ran locked the nuts in place.I wonder if the crank out of the 429 is a complete mismatch with this engine???? I have all the exterior bolted to it also like the intake and exhaust manifolds from the 429.Also the engine runs approximatley 10 to 15 minutes and gets really hot like 212 or hotter.
BUD

Just to help extract info......
.040 over flat tops are for the 429 crank or 460 ?
I think theres different pin height?
Got a piston part number ?

Stock cam .....which one ? 1973 ?
Got any specs?
New valves ......whats the part number or valve lenght?

I am no exspert like Paul Kane is ,....but from what I see in your post,flat tops /dove heads/stock cam......I would think the static compression "might "be a little high and the dynamic compression would be real high,which "could "cause heating issues.
I have no clue on the valve issue,thats why I asked for additional info for Paul or whoever may help.

The pistons came with the block after being bored and also the cam and lifters were in it.The reason for the crank from my old 429 is the crank that belonged in it was all chewed up on the key way end .Thanks for your response shawnlee28

Checked the pushrod length and it is 8.675 I believe paul said in one of his articles this is stock.Anyhow that is what I have.Thank you for your advice and help.BUD P.S were are you located in IL. I grew up in Spfld spent 16 years there.

They are on my page with the post or should be I think if you click on the camera they will show up .Bud

Ok I will pull the rocker covers off and shoot them for you.Anything to get to the bottom of this issue as Im not getting any younger.Thanks for your concern and time Denny W
BUD Ok they are posted for you to take a look maybe see something I dont.

Are those rockers the ones that capture the valve tip?I do not see any guide plates..............